The Evo Drift Purge Combo features a single lens mask with a purge valve and a semi-dry snorkel. The mask and snorkel are constructed with hypoallergenic, soft durable silicone for maxium comfort. The Drift Purge Mask includes a purge valve which keeps your mask clear of leaked-in water. The Semi-Dry Snorkel has a drop-away flex mouthpiece, to streamline your gear when not in use. The top of the barrel of this snorkel guards against water entering the surface, while the mouthpiece has a large purge for easy clearing.